Scott Kelly captured this photo during his first spacewalk last week with Kjell Lindgren. Today (Nov. 6) the duo is heading out again to reconfigure a station cooling system over the course of 6.5 hours.

American astronauts Scott Kelly and Kjell Lindgren are venturing outside the International Space Station this morning (Nov. 6) for their second spacewalk mission in two weeks — and you can watch their orbital action online as it happens.

The 33rd U.S. spacewalk outside the station began at 6:22 a.m. EST (1122 GMT), and the astronauts will be reconfiguring a station cooling system after an attempt to stop a leak in 2012, and topping off its liquid ammonia. Spacewalkers rerouted the ammonia in 2012 to isolate the leak, but traced the leak to another component in 2013. The astronauts are scheduled to be outside for 6.5 hours to make the changes, although they can stay out longer if necessary.

"We have to do a lot of tasks that are jam-packed into a single EVA," Arthur Thomason, the lead U.S. 33 spacewalk officer, said in a news conference broadcast on NASA TV Oct. 22. "We have high confidence it's going to fit …The biggest thing is just keeping things moving, and if we do run into any kind of unexpected issue, working through that quickly and finding a way to resolve the problem."

Over the course of the spacewalk, Kelly and Lindgren will work with tanks and cables carrying liquid ammonia, so they have been trained in how to respond if highly toxic ammonia flakes make contact with their spacesuits to ensure they don't carry them back inside. The choreography for the astronauts' tasks has been worked out in NASA's underwater Neutral Buoyancy Laboratory at Johnson Space Center in Houston.

As in last week's spacewalk, Japanese astronaut Kimiya Yui will assist in the astronauts' preparation and exit from the space station, while also helping coordinate from inside during the mission. The six-person crew, which also includes Russian cosmonauts Sergey Volkov, Mikhail Kornienko and Oleg Kononenko, recently celebrated 15 years of continual human presence in the International Space Station.

Check back this afternoon for Space.com's wrap-up of the spacewalk mission.